Sediment transport and siltation of brown trout (Salmo trutta L.) spawning gravels in chalk streams

Sediment loads and sources in heavily modified Irish catchments: A move towards informed management strategies

“…Acornley and Sear (1999) concluded that accumulation of fine sediments in spawning redds was highest during spawning in the winter period in the River Test, U.K. This paper's observation of fine sediment delivery to salmon redds supports this supposition.…”

Influence of hydrologic attributes on brown trout recruitment in low-latitude range margins

“…These velocities are common in the study rivers during the emergence periods of some years (Table 1). In addition, high flow pulses in the study area are typically associated with sediment transport increases followed by further accumulation in the stream bed, which can physically trap alevins, preventing their emergence (Acornley and Sear 1999;Hartman and Hakala 2006). In Hoz Seca, Eresma, and Cega, survival rate was also negatively influenced by the rate of change in discharge (reversals and rise rate) during the emergence period, which can quickly influence habitat availability and suitability for young trout (Olden and Poff 2003;Ayllón et al 2009), and therefore limit recruit abundance within the sites.…”

Environmental threats and conservation implications for Atlantic salmon and brown trout during their critical freshwater phases of spawning, egg development and juvenile emergence

“…However, in case of high fine material loads, the substrate can quickly colmate again. Since winter spawning salmonids have a long egg development time (up to five months) (Acornley & Sear, 1999; Mueller et al, 2014; Soulsby et al, 2001; Sternecker et al, 2014), it can happen that the gravel cleaned by the female prior to egg deposition does not remain so through the development time of the eggs. Eggs of other salmonids, such as grayling or Danube salmon, which are laid in spring (Northcote, 1995; Sternecker et al, 2014), develop faster due to the higher ambient water temperature and thus have a shorter exposure time (Sternecker et al, 2014).…”

“…heavy metals, pesticides, pharmaceuticals) or nutrients potentially bound to the fines (Kemp et al, 2011). Fine material falling through the upper, coarser, gravel layers fills the spawning redd from the bottom up (Acornley & Sear, 1999; Einstein, 1968; Pander et al, 2015; Turnpenny & Williams, 1980). In such a case, shallower spawning redds can replenish faster, which was often observed after gravel bed restoration (e.g.…”